Quantum spin dynamics of quasi-one-dimensional Heisenberg-Ising magnets in a transverse field: confined spinons, E <sub>8</sub> spectrum, and quantum phase transitions
Kirill Amelin, J. Viirok, U. Nagel, T. Rõõm, Johannes Engelmayer, T. Dey, Agustinus Agung Nugroho, T. Lorenz, Zhe Wang
Abstract
Abstract We report on high-resolution terahertz spectroscopic studies of quantum spin dynamics in the quasi-one-dimensional Ising-like ferromagnet CoNb 2 O 6 and antiferromagnet BaCo 2 V 2 O 8 as a function of an applied transverse magnetic field. In the ordered phases stabilized by inter-chain couplings, we reveal characteristics for confined spinon excitations, E 8 dynamical spectrum, and field-induced quantum phase transitions. The connections between these characteristic dynamical features are found in the field-dependent evolution of the excitation spectra.
Topics & Concepts
SpinonPhysicsCondensed matter physicsIsing modelQuantum phase transitionQuantumAntiferromagnetismSpin (aerodynamics)Heisenberg modelField (mathematics)Transverse fieldPhase transitionQuantum mechanicsMathematicsPure mathematicsThermodynamicsAdvanced Condensed Matter PhysicsPhysics of Superconductivity and MagnetismTopological Materials and Phenomena